Bulletin of Environmental Contamination and Toxicology最新文献

The Australian redclaw crayfish, Cherax quadricarinatus, has been introduced globally for aquacultural purposes, and invasive wild populations have established in several countries. An increase in population growth, has caused several low-income and rural communities to utilise it as an inexpensive protein source. Despite this introduction, limited research has been done on element accumulation, and the risks for human consumption. This study focused on elemental accumulation in C. quadricarinatus from two rivers in the Phongolo River Floodplain (PRF), South Africa. The non-carcinogenic and carcinogenic human health risks associated with its consumption were calculated. The accumulation order in the PRF was Zn > Cu > Pb > Cr > As > Ni > Hg > Cd. Elevated concentrations of As and Hg, as well as As, Cr, and Ni posed non-carcinogenic and carcinogenic risks, respectively. These results highlight that wild populations of C. quadricarinatus not only pose a threat to aquatic ecosystems but also potentially cause human health risks when consumed.

Both ibuprofen (IBP) and chlorophene (CP) are frequently detected contaminants in surface aqueous environment. Dissolved organic matter (DOM) is an important component in water with high photo-reactivity, playing an important role in the transformation processes of various organic pollutants. This study systematically studied the influence of DOM on the photochemical transformation of IBP and CP by using humic acid as model DOM. In addition, the effect of inorganic salts on this process is also considered due to the high salt content in the ocean. Further quenching experiments and reactive oxygen species (ROSs) detection were also conducted to explore the reactive species acting on the IBP and CP transformation. Based on the products analysis and theoretical calculation, we proposed the IBP and CP transformation mechanism. Overall, this study provides some new insights into the transformation of organic pollutants in natural surface water, which is significant for assessing the fate of pollutants.

In this study, we conducted an analysis of health risks faced by residents of Salamanca, Mexico, who were exposed to fine particulate matter with a diameter of 2.5 μm (PM_2.5) through inhalation. The characterization and analysis of these particulate matter samples were undertaken. A total of 131 samples were collected from two different sites: 65 from the Red Cross site (RC) and 66 from the Integral Family Development site (DIF) in 2014-2015. These samples were analyzed for a set of chemical components, including metals and ions. Non-cancerous health risk levels associated with PM_2.5 exposure through the human respiratory system, as per the WHO benchmark (assigned a value of 1), revealed notable risk values for two elements: Manganese (Mn) with a range of 1.19-2.12 in the adult population and 1.59-2.84 in the child population, and Nickel (Ni) with a uniform risk value of 1.39 for both evaluated population groups. However, concerns arose regarding potential non-cancerous effects as the cumulative risk levels for various assessed elements showed elevated indices. These ranged from 3.81 to 4.4 in adults and 4.48-5.24 in children. This study provided comprehensive data on composition and its potential impact on human health, offering valuable insights for the implementation of mitigation measures aimed at reducing inhalation-related exposure.

The environmental fate of a plant growth regulator cyclanilide was studied in this paper. The degradation, adsorption, and migration behaviors of cyclanilide were detailly measured in the laboratory. The results showed that the DT₅₀ of cyclanilide degradation in the Jiangxi red, Taihu paddy, Changshu wushan, Shaanxi tide, and Dongbei black soils was 42.3 d, 31.9 d, 14.4 d, 30.4 d as well as 27.4 d under aerobic conditions and 32.3 d, 37.4 d, 29.3 d, 48.9 d as well as 27.0 d under water anaerobic conditions, respectively, with the main metabolite being 2,4-dichloroaniline (2,4-D). The DT₅₀ of 2,4-D ranged from 5.26 to 27.1 days under aerobic conditions, and from 10.6 to 54.1 days under anaerobic conditions. The adsorption of cyclanilide by the soils was well fitted by the empirical linear adsorption isotherm, and the adsorption constant (K_{d, H}) values in the Jiangxi red, Taihu paddy, Changshu wushan, Shaanxi tide, and Dongbei black soils were 7.08, 4.49, 4.05, 3.20, and 1.41, respectively. The results of a mobility test showed that cyclanilide had strong mobility in the most test soils. Furthermore, soil pH is the dominant element affecting the adsorption of cyclanilide in the soils. Under aerobic environment, the DT₅₀ of total cyclanilide in river and lake water-sediment systems were 30.7 d and 34.0 d, respectively; under anaerobic environment, their DT₅₀ were 30.8 d and 31.4 d, respectively. In water-sediment systems, 2,4-D mainly exists in aqueous phase and the DT₅₀ ranged from 5.23 to 8.76 days. This work demonstrated that cyclanilide has the potential risk to contaminate environment and attention should be paid to its application.

Chlorpyrifos (CPF) has been used worldwide, but its possible negative effects on macrophytes have been scarcely studied. The main goal of the present work was to assess the potential phytotoxic effects of CPF on different stages (seed and seedling) of the wetland macrophyte Bidens laevis. During the germination of seeds, stimulation of radicle growth at low concentrations of CPF (10 µg/L) and inhibition of its elongation at 80 µg/L CPF were observed. In seedlings, concentrations ≤ 160 µg/L CPF did not exhibit adverse effects on growth after 7 days of exposure, despite the decrease of photosynthetic pigments and carotenoids observed at 40 µg/L CPF compared to the control. Environmentally relevant concentrations of CPF altered neither oxidative stress biomarkers nor pigment contents in seedlings exposed for 48 h, suggesting CPF would be non-toxic to B. laevis in natural scenarios.

Coastal ecosystems are characterized by various human activities with potential adverse impacts. This study aimed to evaluate the potential oxidative stress effects in representative aquatic biota deployed in situ at a sawmill wastes dump (test site) and reference site in a coastal ecosystem for a short term (28 days) period. PAHs and OCPs were analysed using GC-FID and GC-MS respectively in surface water and sediments. Oxidative stress indices (malondialdehyde, glutathione-s-transferase, reduced glutathione, catalase and superoxide dismutase) were evaluated following standard methods in Coptodon guineensis (Guinean Tilapia) and Callinectes amnicola (Blue crab) over a period of 28 days. Sum PAHs in the test site sediments, oxidative stress indices in C. guineensis liver and C. amnicola haemolymph after 28 days exposure were significantly higher (p < 0.0.5) compared to the reference site. The results showed the adverse impacts to biota of sawmill wastes which are continuously burnt at the test site with potential for long-term effects. Sustainable sawmill wastes management at the test site are recommended to sustain life below water (UNSDG 14).

In the present paper, the assessment of vortex-assisted dispersive magnetic solid-phase extraction using amino-functionalized mesoporous combined with direct magnetic sorbent sampling (DMSS) in flame or furnace atomic absorption spectrometry (FAAS or FF-AAS) was demonstrated for highly sensitive silver determination in water samples. The developed method showed significant enrichment factors compared to conventional pneumatic nebulization by FAAS, 607 for DMSS-FF-AAS and 114 for DMSS-FAAS. The analytical curve showed linearity in the range from 5.0 to 70.0 µg L^- 1 and 1.0 to 15.0 µg L^- 1 and limits of detection of 0.59 and 0.09 µg L^- 1 for DMSS-FAAS and DMSS-FF-AAS, respectively. The intra and inter-day precision evaluated as a percentage of the relative standard deviation (RSD,%) ranged from 1.89 to 4.71% for levels of 25.0 and 65.0 µg L^- 1. The method was applied in different kinds of water samples without matrix effects, yielding recovery values from 90 to 110%.

A field experiment was conducted to study the persistence and reduction of quinalphos residues in cauliflower curd by applying quinalphos 25 EC twice at 250 g a.i./ha at 10 days intervals. The limit of quantification (LOQ) was 0.05 µg/g, recovery ranged from 97 to 113%, and the relative standard deviation was less than 7%. The initial deposition of quinalphos residues in cauliflower curd was 1.72 µg/g and reached below LOQ level after 15 days of application. Dissipation of the residue followed first-order kinetics with a half-life of 2.32 days. The reduction of quinalphos residue was evaluated using various household processes. The greatest reduction (82%) was observed when washing was followed by cooking or boiling, while the smallest reduction (55.8%) was found when washing alone was performed. A waiting period of 9 days is recommended for safe consumption of cauliflower based on the FSSAI MRL value of 0.1 µg/g.

The current study aimed to evaluate the occurrence of microplastics in feed ingredients commonly used as protein and carbohydrate (energy) sources to understand and mitigate microplastic contamination. Microplastics average was 1.27, 0.69, 2.85, 0.55, 0.07, and 0.17 particle g^- 1 in fishmeal, soybean meal, poultry by-products, rice bran, wheat bran, and wheat flour, respectively. Notably, poultry by-products demonstrated significantly higher microplastic levels than other ingredients (p < 0.05). The dominant microplastic shape was microfibers, with prevalent sizes ranging from 500 to 1000 μm. We estimated that packaging materials are a significant source of pollution due to the high presence of polypropylene and other polymers. Top aquaculture species with the greatest microplastic exposure risk include the Catla catla, Hypophthalmichthys nobilis, and Oreochromis niloticus. This research extends our knowledge of microplastic pathways, contributes to improving aquafeed quality, and provides the basis for determining the risk of microplastic exposure in aquafeed.

In the present study, we aimed to determine the parameters of oxidative stress markers, motility and kinematics of rainbow trout (Oncorhynchus mykiss) sperm cells exposed to different doses (0.001, 0.01, 0.1, 1.0, and 10 mg/L, in vitro 4 h) of tire rubber based microplastic particles (TRMP-Ps) the leachates procedure of rubber pieces. First of all, TRMP-Ps were prepared by abrasion method in accordance with the literature. Structural and morphological features of TRMP-Ps were determined by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) methods, respectively. Energy dispersive X-ray (EDX) analysis technique was used to characterize the elemental composition of TRMP-Ps. Particle size of microplastic structures was measured hydrodynamically with dynamic light scattering analysis (DLS). After exposure, the effect of TRMP-Ps was defined by the observations of kinematics and antioxidant activities in sperm cells. Our findings showed that the straight line velocity, the curvilinear velocity, the angular path velocity, and the amplitude of lateral displacement of sperm cells decreased. Moreover, while the level of superoxide dismutase decreased dose-dependently against the toxicity of TRMP-Ps, no significant change was observed in the levels of malondialdehyde and total glutathione. The 4-h median effective concentrations (EC₅₀) of TRMP-Ps based on mobility parameters of sperm ranged from 0.31 mg/L for reduced straight line velocity of sperm cells to 0.51 mg/L for reduced amplitude of lateral displacement of the spermatozoa head. Therefore, we concluded that TRMP-Ps can be a risk for the reproduction cycle of fish in aquatic environments.